Various means have been used in the prior art to provide troops with a closed combustion cartridge which, upon expulsion of a round therefrom, would not reveal the firing location of the gunner. The importance of a smokeless, flashless, low noise weapon system is of particular importance whenever it is desired to use a hand held, shoulder fired grenade launching weapon against out of line-of-sight targets. Munitions fired from closed combustion cartridges which may be armed by set back and spin forces and exploded upon impact with a target have been disclosed in the prior art in U.S. Pat. No. 3,738,271 of Nicholas J. LaCosta. However, prior art sealed cup cartridges of the smokeless, flashless type have failed to solve the problem of expelling a signal projectile which must have its delay trains initiated while in the launching weapon. Short delays are necessary whenever it is desired to have a signal projectile operate only several hundreds of feet away from the launch site. Prior art closed combustion cartridges merely solved the problem of propelling the round from the cartridge without evidence of smoke, flash and low noise, but did not provide the necessary combination of elements in their structure to assure quick ignition of the delay train of a projectile or a signal device which had to operate at a burst height range of 500 to 700 feet above ground.